San Diego has no immediate plans to add a running back in free agency, a team source said, as the organization's attention, for now, centers on evaluating the running backs currently in place.

Once Mike Tolbert departed via free agency, a question arose over who'd become the Chargers' next featured running back on third down.

They have options, coach Norv Turner said Thursday.

“We're working hard to get real comfortable with who we think the third-down back is," Turner said. "Right now, Ryan (Mathews) would be that guy, but (Curtis) Brinkley has done it, and there's certain times where I could see Le'Ron McClain doing it because he's an excellent receiver and a very good pass protector.”

Last year, Mathews was productive in the role when used.

He moved the chains on 10 of his 15 third-down touches, totaling nine carries for 92 yards with six catches for 59. Earlier this week, Turner said the Chargers will give him "everything he can handle."

As they measure which back is best for various situations, rookies Edwin Baker, a seventh-round draft pick, and Michael Hayes, who went undrafted, are being assessed.

"I like them," Turner said. "They're two explosive guys. Baker, obviously, you know more about when you draft a guy. He's got great quickness, great explosion and acceleration. Michael Hayes has been a pleasant surprise because he's got some juice, and he catches the ball real well. It's going to be fun having them in camp."

The team could sign a running back closer toward or even during training camp, which begins late July. There's no guarantee he'd make the team, and the contract would likely be for the veteran minimum.

A reserve cornerback is also expected to be added for the veteran minimum.

Quentin Jammer, Antoine Cason, Marcus Gilchrist and Shareece Wright currently top the depth chart at corner. Gilchrist received reps at nickel back during the first week of organized team activities, which will resume next Tuesday.

Gilchrist and Wright have both made promising strides entering their second seasons, Turner said.

Wright played more sparingly as a rookie. He contributed mostly on special teams, seeing just four defensive snaps.

"He's a really talented player," Turner said. "I think people are going to notice him when we play in games."